Last Monday, Luis's parents gave birth to twins and named them Jessica and Michael. When they were first born, Jessica weighed 7.51 pounds and was 19.5 inches tall, and Michael weighed 8.48 pounds and was 18.5 inches tall. How much did the babies weigh in total?
Solution: To find the weights of the 2 babies, we need to add their weights together. Jessica's weight + Michael's weight = total weight. ${7}$ ${5}$ ${1}$ ${8}$ ${4}$ ${8}$ ${+\vphantom{0}}$ ${9}$ ${9}$ ${5}$ ${1}$ Together, the babies weigh 15.99 pounds.